The traditional game of tether ball has undergone substantial refinements in recent years leading to the well known game comprising a helix mounted on a pole and a ball attached to a line which is attached at its other end slidably with the helix so that the point of attachment moves up or down the helix according to the direction of travel of the ball after being struck by a bat. The game is generally played by two persons, each attempting to hit the ball in opposite directions and the winner is he who manages to cause the point of attachment to travel to its lowermost or highermost position on the helix, depending on the direction in which he is required to strike the ball.
Two main designs of helix have been suggested--one being a spiral, in which case the point of attachment is a ring or the like slidable on the spiral; and the other being a threaded bolt member in which case the point of attachment is a nut element rotatable thereon.
In both cases a problem can arise between players as to whether the line attachment has moved to an end position relative to the helix (which would indicate the end of a particular game) before the player defending that end position has managed to reverse the direction of the ball and therefore the movement of the line attachment relative to that end position.
In the case of the spiral it has been proposed (U.K. Patent No. 1 557 479) to provide bi-modal indicating means which are operable to change mode abruptly on movement of line attachment into either of its two end positions, to provide a perceptible signal. In one example of that invention a sleeve element is provided which is slidable on a pole inside the spiral between a cocked position, triggering formations at either end of the spiral adapted to release the sleeve on contract of the line attachment therewith, whereby the sleeve element is released from its cocked position with the accompanying emission of a signal--for example the visual signal of its rapid movement which may be accompanied by a clicking noise.
As far as the Applicant is aware, no such indicating means have been suggested for the nut-and-bolt type of tether ball game and it is an object of the present invention to provide such means.